When a plurality of devices, apparatuses and the like are installed on construction while their positions are being adjusted accurately, there are cases where reference points for alignment are set on the construction in advance, in order to perform the work and control efficiently. In case of maglev system (i.e. a linear motor vehicle system), for example, a guideway for the traveling track is constructed made of structural members such as concrete and steel materials, and a plurality of ground coils (superconducting coils) that cause vehicles to float and propel over the guideway are installed along a longitudinal direction of the guideway. In general, the guideway structured with concrete allows for a construction tolerance of about 2 cm to 3 cm, whereas the ground coils are required to be structured with high accuracy, the tolerance being at most 2 mm or 3 mm, in order to assure a comfortable ride and security for floating type vehicles traveling at high speeds. For that purpose, a method of structuring ground coils with desired accuracy is employed, in which a plurality of reference points whose 3D coordinates are determined are set at the center of a guideway, or a construction, along a longitudinal direction of the guideway with high accuracy in advance, and then ground coils are structured while their relative locations to these reference points or differences in altitude therebetween are measured and controlled (refer to Non-Patent Document No. 1).
Referring to FIG. 9, for example, it is assumed that a plurality of large-sized apparatuses 5 such as a high energy accelerator device, a proton beam therapy (cancer-therapy) device, or a particle beam therapy (cancer-therapy) device, are installed in a building construction 1 such as a research facility or medical facility. In FIG. 9, the large-sized apparatuses 5 include an accelerator 5a, a conveying pipe line 5b, a radiation apparatus 5c, a treatment table 5d, etc. In order to obtain a high quality energy-beam, proton-beam or particle-beam, each apparatus is required to be installed with extremely high accuracy, the tolerance being about 0.01 mm to 0.1 mm (10 μm to 100 μm) (refer to Non-Patent Document Nos. 2 and 3). For that purpose, such method of installing the apparatuses 5a, 5b, 5c and 5d is employed that a plurality of reference points S1 to S24 with determined 3D coordinates are set in advance on the floor of the construction 1 on which the apparatuses are to be installed with high accuracy, and then the positions of the apparatuses 5a, 5b, 5c and 5d are adjusted while their relative locations to each of the reference points S1 to S24 and differences in altitude therebetween are controlled. The reference points may be set on the wall and/or the ceiling of the construction 1, when necessary.
The method of installing the apparatuses 5a, 5b, 5c and 5d by using the reference points S1 to S24 as shown in FIG. 9 will be described below to the extent of the need to understand the present invention.
(1) First, the plurality of reference points S1 to S24 are selected within a fixed area on the construction 1, and targets for surveying are set at these reference points.
(2) Then, 3D coordinates of each reference point S are measured with a surveying instrument. The typical surveying instrument may be a total station or TST (total station theodolite) configured by integrating a phase difference detecting type lightwave distance meter with a theodolite (angle measuring instrument). More specifically, the center of the surveying instrument is aligned with the reference point S1. Then, the surveying instrument at the reference point S1 collimates the target at the reference point S2, and determines the lateral and vertical angles and length of the survey line. In this manner, 3D coordinates of the reference point S2 are measured in a coordinate system that has an origin at the reference point S1. Following this, the surveying instrument is moved to the reference point S2, and the center of the surveying instrument is aligned with the reference point S2. Then, the surveying instrument at the reference point S2 collimates the target at the reference point S3, and determines the lateral and vertical angles and length of the survey line. In this manner, 3D coordinates of the reference point S3 are measured in the same coordinate system. By sequentially repeating a cycle of collimating the target at a reference point S (n+1) to measure its 3D coordinates by using the surveying instrument aligned with a reference point Sn likewise, 3D coordinates of all the reference points S are measured in the same coordinate system. Finally, errors contained in the measured coordinates of each reference point are minimized with the network-adjustment calculation. As a result, 3D coordinates of the reference points S1 to S24 are determined (generally known as “open-traverse surveying method”).
(3) After 3D coordinates of each reference point S are surveyed, the apparatuses 5a, 5b, 5c and 5d are installed at required locations within the construction 1 while their relative locations to each reference point S and differences in altitude therebetween are being measured with a 3D measuring instrument. More specifically, additional targets are mounted on the apparatuses 5a, 5b, 5c and 5d, and then the 3D measuring instrument collimates each target to determine 3D vector from the center of the measuring instrument (center of the machine) to each target. For example, the 3D measuring instrument at the same location determines the respective 3D vectors for the targets at the reference points S and the targets on the apparatuses 5a, 5b, 5c and 5d. Then, the apparatuses 5a, 5b, 5c and 5d are installed while their relative locations to each reference point S and differences in altitude therebetween are calculated accurately from 3D vectors. A typical example of such a 3D measuring instrument may be a laser tracker configured by integrating an optical interferometric type laser distance meter with a theodolite, or a 3D total station configured by integrating a phase difference detecting type lightwave distance meter with a theodolite. Using a laser tracker or a 3D total station enables the relative locations of the apparatuses 5a, 5b, 5c and 5d to each reference point S and differences in altitude therebetween to be measured with high accuracy, the tolerance being at most 10 μm to 100 μm (refer to Patent Document Nos. 1, 2 and Non-Patent Document No. 3).